The present disclosure relates to control devices, control methods, and exposure control systems.
In recent years, an imaging apparatus, such as a digital camera, equipped with an imaging element having a plurality of photo-electric converters and in which the pixels thereof are divided is becoming widely available. By using such an imaging element, a phase-difference-detection autofocus (sometimes referred to as “phase-difference AF” hereinafter) mode that allows for high-speed autofocusing becomes possible.
For example, JP 2008-134389A discloses a method for controlling an imaging apparatus that uses an imaging element including phase-difference AF pixels and normal pixels. In JP 2008-134389A, phase-difference AF is performed by using the phase-difference AF pixels, whereas contrast autofocus (AF), live-view display, an automatic exposure (AE) process, and an auto-white-balance (AWB) process are performed by using the normal pixels.
JP 2008-300931A discloses a technology that compensates for storage time by performing specific gain correction on each line within an AF frame when the AF frame and a monitor-display frame are alternately read for improving both monitor image quality and focus precision. This avoids a situation where the storage time within the frame becomes uneven, and appropriate exposure is obtained for both the AF frame and the monitor-display frame.